NEW YORK // Top-ranked Ana Ivanovic suffered one of the biggest upsets in tennis history when she was stunned by 188th-ranked Julie Coin of France 6-3, 4-6, 6-3 in the second round of the US Open yesterday. Never before in the Open era that began in 1968 had the No. 1 woman lost this early in the tournament. Coin screamed when Ivanovic's last shot sailed out, then hopped for joy and hit an extra ball high into Arthur Ashe Stadium. Ivanovic quickly gathered her gear and left the court, her hopes of another grand slam championship dashed. "Obviously, if you would ask me at the moment if I'm playing like a No. 1, probably not," Ivanovic conceded. "It's very frustrating because I know I can play so much better." Even after Ivanovic struggled in the first round while coming back from an injured thumb, there was no way to see this coming. Coin spent much of the year playing in minor events and was nearly knocked out in Open qualifying. The 25-year-old Frenchwoman recently played so poorly she thought about giving up the sport and relying on her mathematics degree. "I was thinking, 'Am I really made to play tennis?'" she said. Asked whether she thought such a win was possible, she gave a direct, honest answer. "No," she said. And when did she believe it might happen? "I guess when it was over," she told the crowd, drawing a huge ovation. If there was any suspicion that Coin was wavering, she steadied herself by rallying in the third set. It was Ivanovic who looked jittery, hitting shots directly into the net or way out. Top-seeded Rafael Nadal avoided a similar fate on the men's side, beating the American qualifier Ryler De Heart 6-1, 6-2, 6-4. Nadal joined Venus and Serena Williams, James Blake, David Ferrer, Andy Murray and Dinara Safina in moving into the third round. No. 14 Ivo Karlovic posted the stat of the day while beating Florent Serra of France in straight sets - he finished ahead in aces 42-0. The Ivanovic-Coin match was originally scheduled for the smaller Louis Armstrong Stadium, but was moved to the main Ashe stage to give the crowd a treat. The fans hardly knew what really was in store. Tentative at times, Ivanovic seemed to regain her edge midway through third set. She led 40-0 in the fifth game and was about to break Coin's serve when suddenly the momentum shifted. Coin came back to hold, starting her decisive streak. Ivanovic tried to stave off Coin in the final game, but it was too late for the 20-year-old Serbian star. Coin won on her third match point - quite a result for someone playing in her first tour-level event. Coin had failed to qualify for the Australian Open, French Open and Wimbledon. And she certainly was not anything bankable going into this match - she'd earned less than US$100,000 (Dh367,000) as a pro, and was facing someone who had won nearly US$6 million. Next up for Coin in the third round is compatriot Amelie Mauresmo, who beat Kaia Kanepi of Estonia 2-6, 6-4, 6-0. Coin and Mauresmo once played at the same club near Paris and shared the same coach, though they do not know each other well. "I know she was No. 1," Coin said. Going into this Open, Ivanovic had played only two matches since Wimbledon while her thumb healed. The injury forced her to withdraw from the Olympics before they began, limited her practice time, and sent her from Beijing to Australia for treatment. Fourth-seeded Serena Williams routed Elena Vesnina of Russia 6-1, 6-1 and seventh-seeded Venus Williams overwhelmed Rossana de Los Rios of Paraguay 6-0, 6-3. "I'm very satisfied so far, the way it's gone," Venus said. Venus breezed past an opponent ranked 117th. After teaming with her sister to win Olympic gold in doubles, she stayed on course to play Serena in the quarter-finals in the US Open. "Whichever way the draw goes, whichever way the matches go, as long as hopefully it's a win for me, I'm pretty happy about it," she said. Williams is the last woman to win consecutive championships at the US Open, but has not taken the title since 2001. "Oh yes, I remember. I won't forget, but I'd like to have a more recent memory as of, like, '08," she said. "Kind of overdue." Among the other winners were Agnieszka Radwanska, Alize Cornet, Dominika Cibulkova and Nadia Petrova. But Nicole Vaidisova lost to Severine Bremond of France 7-5, 6-3. The sixth-seeded Safina, not nearly as volatile as brother Marat Safin, played under control in beating Roberta Vinci of Italy 6-4, 6-3. On the men's side, fourth-seeded Ferrer beat Andreas Beck of Germany 4-6, 7-5, 6-3, 7-6 (5), sixth-seeded Murray defeated Michael Llodra of France 6-4, 1-6, 7-5, 7-6 (7) and Argentine teenager Juan Martin del Potro notched his 21st straight win, beating Thomaz Bellucci of Brazil 4-6, 6-1, 7-5, 6-3.